Note 3 - Loans (Detail) - Allowance For Loan Losses And Recorded Investment In Loans By Portfolio Segment (USD $) In Thousands, unless otherwise specified	3 Months Ended		9 Months Ended										3 Months Ended		9 Months Ended										3 Months Ended		9 Months Ended									3 Months Ended		9 Months Ended									3 Months Ended		9 Months Ended									3 Months Ended		9 Months Ended
	Sep. 30, 2012	Sep. 30, 2011	Sep. 30, 2012	Sep. 30, 2011	Dec. 31, 2011	Sep. 30, 2011 Commercial And Industrial [Member] Period Beginning [Member] Prior Period [Member]	Sep. 30, 2012 Commercial And Industrial [Member] Period Beginning [Member]	Jun. 30, 2012 Commercial And Industrial [Member] Period Beginning [Member]	Sep. 30, 2011 Commercial And Industrial [Member] Period Beginning [Member]	Sep. 30, 2011 Commercial And Industrial [Member] Period Ending [Member] Prior Period [Member]	Sep. 30, 2012 Commercial And Industrial [Member] Period Ending [Member]	Sep. 30, 2011 Commercial And Industrial [Member] Period Ending [Member]	Sep. 30, 2012 Commercial And Industrial [Member]	Sep. 30, 2011 Commercial And Industrial [Member]	Sep. 30, 2012 Commercial And Industrial [Member]	Sep. 30, 2011 Commercial And Industrial [Member]	Dec. 31, 2011 Commercial And Industrial [Member]	Sep. 30, 2011 Real Estate Mortgage [Member] Period Beginning [Member] Prior Period [Member]	Sep. 30, 2012 Real Estate Mortgage [Member] Period Beginning [Member]	Jun. 30, 2012 Real Estate Mortgage [Member] Period Beginning [Member]	Sep. 30, 2011 Real Estate Mortgage [Member] Period Beginning [Member]	Sep. 30, 2011 Real Estate Mortgage [Member] Period Ending [Member] Prior Period [Member]	Sep. 30, 2012 Real Estate Mortgage [Member] Period Ending [Member]	Sep. 30, 2011 Real Estate Mortgage [Member] Period Ending [Member]	Sep. 30, 2012 Real Estate Mortgage [Member]	Sep. 30, 2011 Real Estate Mortgage [Member]	Sep. 30, 2012 Real Estate Mortgage [Member]	Sep. 30, 2011 Real Estate Mortgage [Member]	Dec. 31, 2011 Real Estate Mortgage [Member]	Sep. 30, 2011 Real Estate Construction [Member] Period Beginning [Member] Prior Period [Member]	Sep. 30, 2012 Real Estate Construction [Member] Period Beginning [Member]	Jun. 30, 2012 Real Estate Construction [Member] Period Beginning [Member]	Sep. 30, 2011 Real Estate Construction [Member] Period Beginning [Member]	Sep. 30, 2012 Real Estate Construction [Member] Period Ending [Member]	Sep. 30, 2011 Real Estate Construction [Member] Period Ending [Member]	Sep. 30, 2012 Real Estate Construction [Member]	Sep. 30, 2011 Real Estate Construction [Member]	Sep. 30, 2012 Real Estate Construction [Member]	Sep. 30, 2011 Real Estate Construction [Member]	Dec. 31, 2011 Real Estate Construction [Member]	Sep. 30, 2011 Consumer And Other [Member] Period Beginning [Member] Prior Period [Member]	Sep. 30, 2012 Consumer And Other [Member] Period Beginning [Member]	Jun. 30, 2012 Consumer And Other [Member] Period Beginning [Member]	Sep. 30, 2011 Consumer And Other [Member] Period Beginning [Member]	Sep. 30, 2012 Consumer And Other [Member] Period Ending [Member]	Sep. 30, 2011 Consumer And Other [Member] Period Ending [Member]	Sep. 30, 2012 Consumer And Other [Member]	Sep. 30, 2011 Consumer And Other [Member]	Sep. 30, 2012 Consumer And Other [Member]	Sep. 30, 2011 Consumer And Other [Member]	Dec. 31, 2011 Consumer And Other [Member]	Sep. 30, 2011 Unallocated [Member] Period Beginning [Member] Prior Period [Member]	Sep. 30, 2012 Unallocated [Member] Period Beginning [Member]	Jun. 30, 2012 Unallocated [Member] Period Beginning [Member]	Sep. 30, 2011 Unallocated [Member] Period Beginning [Member]	Sep. 30, 2012 Unallocated [Member] Period Ending [Member]	Sep. 30, 2011 Unallocated [Member] Period Ending [Member]	Sep. 30, 2012 Unallocated [Member]	Sep. 30, 2011 Unallocated [Member]	Sep. 30, 2012 Unallocated [Member]	Sep. 30, 2011 Unallocated [Member]	Sep. 30, 2011 Period Beginning [Member] Prior Period [Member]	Sep. 30, 2012 Period Beginning [Member]	Jun. 30, 2012 Period Beginning [Member]	Sep. 30, 2011 Period Beginning [Member]	Sep. 30, 2011 Period Ending [Member] Prior Period [Member]	Sep. 30, 2012 Period Ending [Member]	Sep. 30, 2011 Period Ending [Member]
Allowance for loan losses						$ 8,187	$ 7,966	$ 9,146	$ 7,136		$ 8,636	$ 7,325						$ 22,016	$ 19,213	$ 16,151	$ 20,590		$ 15,565	$ 19,710						$ 1,993	$ 320	$ 185	$ 490	$ 179	$ 493						$ 194	$ 137	$ 106	$ 152	$ 131	$ 151						$ 1,367	$ 685	$ 1,723	$ 2,025	$ 1,031	$ 2,289					$ 33,757	$ 28,321	$ 27,311	$ 30,393		$ 25,542	$ 29,969
Ending allowance for loan losses balance for loans individually evaluated for impairment	976	1,024	976	1,024						275			23	275	23	275						749			953	749	953	749																																						1,024
Ending allowance for loan losses balance for loans collectively evaluated for impairment	23,535	26,656	23,535	26,656									8,613	7,051	8,613	7,051									14,612	18,961	14,612	18,961								179	493	179	493								131	151	131	151
Loans:
Loans	1,100,060	1,062,565	1,100,060	1,062,565	1,048,006								377,309	346,254	377,309	346,254	345,565								708,121	705,757	708,121	705,757	688,352							7,907	6,925	7,907	6,925	10,335							6,723	3,629	6,723	3,629	3,754
Recorded investment in loans individually	40,291	48,270	40,291	48,270									7,357	13,520	7,357	13,520									27,441	34,749	27,441	34,749								5,492		5,492									1	1	1	1
Recorded investment in loans collectively	1,059,769	1,014,295	1,059,769	1,014,295									369,952	332,734	369,952	332,734									680,680	671,008	680,680	671,008								2,415	6,925	2,415	6,925								6,722	3,628	6,722	3,628
Provision for loan losses	(300)	875	300	2,450									922	527	2,531	1,865									(574)	74	(3,166)	1,907								(6)	(2)	523	(2,222)								50	12	66	(22)								(692)	264	346	922
Charge-offs	(1,625)	(1,965)	(4,448)	(7,944)									(1,464)	(597)	(2,258)	(3,222)									(130)	(1,350)	(1,415)	(4,673)										(683)									(31)	(18)	(92)	(49)
Recoveries	156	666	1,369	1,706									32	260	397	496									118	396	933	460									5	19	722								6	5	20	28
Allowance for loan losses		$ 29,969		$ 29,969		$ 8,187	$ 7,966	$ 9,146	$ 7,136		$ 8,636	$ 7,325		$ 7,326		$ 7,326		$ 22,016	$ 19,213	$ 16,151	$ 20,590		$ 15,565	$ 19,710		$ 19,710		$ 19,710		$ 1,993	$ 320	$ 185	$ 490	$ 179	$ 493		$ 493		$ 493		$ 194	$ 137	$ 106	$ 152	$ 131	$ 151		$ 151		$ 151		$ 1,367	$ 685	$ 1,723	$ 2,025	$ 1,031	$ 2,289		$ 2,289		$ 2,289	$ 33,757	$ 28,321	$ 27,311	$ 30,393		$ 25,542	$ 29,969